Are We About to Cure Sickle-Cell Disease?

In September, 1904, a twenty-year-old Grenadian man named Walter Clement Noel disembarked in New York after an eight-day voyage from Barbados. At the time, few Black people were permitted to study at most American universities, but Noel—who was well off, well educated, and a foreigner—had secured a spot at the Chicago College of Dental Surgery. During his journey, he’d developed a painful sore on his ankle; after clearing customs and immigration, he sought out a doctor, who applied a tincture of iodine to the wound. The ulcer healed, leaving a scar similar to others on his body. Noel headed to dental school. But, by Thanksgiving, he’d developed a cough and serious trouble breathing. He felt weak, dizzy, and feverish. A few weeks later, he stumbled into a hospital, where a medical resident named Ernest Irons studied Noel’s blood under a microscope.

The findings were so unusual that Irons immediately alerted his supervising physician, James Herrick. Red blood cells normally look like smooth disks—tiny saucers, concave on both sides, that shuttle oxygen around the body. But Noel’s blood, Herrick later wrote...